Some things on debug should be higher log levels

[pontus]

Running with a "normal" log level (such as info) will leave out a lot of useful info, even when users get 5nn and other errors. I'd want at least any user visible problems (e.g. https://github.com/neicnordic/sda-s3proxy/blob/master/proxy.go#L80-L81) to be notable in the logs.